Gather types during loading instead another walk

3 files changed, 9 insertions, 15 deletions

diff --git a/chapter28b/src/main/java/com/seaofnodes/simple/Parser.java b/chapter28b/src/main/java/com/seaofnodes/simple/Parser.java
index b9cd9658..8410bf5c 100644
--- a/chapter28b/src/main/java/com/seaofnodes/simple/Parser.java
+++ b/chapter28b/src/main/java/com/seaofnodes/simple/Parser.java
@@ -101,6 +101,9 @@ public class Parser {
     ScopeNode _continueScope;   // Merge all the while-continues here
     ScopeNode _returnScope;     // Merge all the function exits  here
     Ary<FRefNode> _frefs;       // Forward refs created during this parse
+    // Layouts needed by field accesses in this source file.  Resolve after
+    // parsing, since a later local struct declaration can satisfy the use.
+    public final LinkedHashSet<String> _requiredTypes = new LinkedHashSet<>();
     TypeStruct _ctorOpenStruct; // Open struct being initialized by an allocation constructor block.
     // Constructor exit types survive scope teardown until all fields are known.
     // A null entry denotes a constructor with no returning path.
@@ -171,6 +174,7 @@ public class Parser {
         assert _frefs == null;
         _lexer = new Lexer(ref);
         _frefs = new Ary<>(FRefNode.class);
+        _requiredTypes.clear();
         // Starting Scope has control, memory, initial arguments
         _scope = new ScopeNode();
         _scope.define(ScopeNode.CTRL, Type.CONTROL   , false, null, _lexer);
@@ -2751,6 +2755,8 @@ public class Parser {
     }
     // Field offset for an unknown type
     public Node fldoff( Node n, String name ) {
+        if( n._type instanceof TypeMemPtr ptr && ptr._obj._fref )
+            _requiredTypes.add(ptr._obj._name);
         return new FldOffNode(n,name,loc()).peephole();
     }
     public Node peep( Node n ) {
diff --git a/chapter28b/src/main/java/com/seaofnodes/simple/codegen/CodeGen.java b/chapter28b/src/main/java/com/seaofnodes/simple/codegen/CodeGen.java
index c2cd657f..561fdece 100644
--- a/chapter28b/src/main/java/com/seaofnodes/simple/codegen/CodeGen.java
+++ b/chapter28b/src/main/java/com/seaofnodes/simple/codegen/CodeGen.java
@@ -625,14 +625,6 @@ public class CodeGen {
     // Last check for bad programs
     public CodeGen typeCheck() { return phase(Phase.TypeCheck, _phase==Phase.FinalizeIR, () -> TypeCheck.run(this)); }
 
-    public static TypeStruct requiredStruct(Node n) {
-        // CNC: remove? cleanup?
-        if( n instanceof NewNode alloc )  return alloc._ts;
-        if( n instanceof ConFldOffNode off ) return off._ts;
-        if( n instanceof FldOffNode off && off.in(0)._type instanceof TypeMemPtr ptr ) return ptr._obj;
-        return null;
-    }
-
     // ---------------------------
     // TypeCheck queued surviving CLInits during its existing error walk.
     public CodeGen lower() {
diff --git a/chapter28b/src/main/java/com/seaofnodes/simple/codegen/ParseAll.java b/chapter28b/src/main/java/com/seaofnodes/simple/codegen/ParseAll.java
index 10b8fd9b..1d9731fc 100644
--- a/chapter28b/src/main/java/com/seaofnodes/simple/codegen/ParseAll.java
+++ b/chapter28b/src/main/java/com/seaofnodes/simple/codegen/ParseAll.java
@@ -198,13 +198,9 @@ public abstract class ParseAll {
     }
 
     private static void addRequiredTypes(CodeGen code, CompUnit cunit) {
-        LinkedHashSet<String> required = new LinkedHashSet<>();
-        code._stop.walk(n -> {
-            TypeStruct ts = CodeGen.requiredStruct(n);
-            if( ts!=null && ts._fref ) required.add(ts._name);
-            return null;
-        });
-        for( String typeName : required ) {
+        for( String typeName : code.P._requiredTypes ) {
+            // A forward use can have been resolved later in this source file.
+            if( Parser.TYPES.get(typeName) instanceof TypeStruct ts && !ts._fref ) continue;
             try {
                 CompUnit xcunit = findRequiredType(code,cunit,typeName);
                 if( xcunit != null )